# SEO Optimization
**Technical SEO, content optimization, and search strategy**
# Technical SEO Skill
**Production-tested practices for technical SEO audits and implementation**
This skill codifies technical SEO best practices from professional audits of high-performing websites.
---
## Core Principles
1. **Crawlability First**: Search engines must find and access your content
2. **Speed Matters**: Core Web Vitals directly impact rankings
3. **Mobile-First**: Google indexes mobile version primarily
4. **Structured Data**: Help search engines understand your content
5. **User Experience**: Technical SEO serves human visitors
---
## The 10 Pillars of Technical SEO
### 1. Site Architecture & Crawlability
**Optimal Site Structure**:
```
Homepage (Level 0)
├─ Category Pages (Level 1)
│ ├─ Subcategory Pages (Level 2)
│ │ └─ Individual Pages (Level 3)
```
**Best Practices**:
- Maximum 3 clicks from homepage to any page
- Logical URL hierarchy
- Clear navigation structure
- Internal linking strategy
- XML sitemap for all important pages
**robots.txt Configuration**:
```txt
# Allow all crawlers
User-agent: *
Allow: /
# Block sensitive areas
Disallow: /admin/
Disallow: /api/
Disallow: /private/
Disallow: /*.pdf$
# Block duplicate content
Disallow: /*?sort=
Disallow: /*?page=
# Sitemap location
Sitemap: https://example.com/sitemap.xml
```
**Common Mistakes**:
- Blocking important pages in robots.txt
- Orphaned pages (no internal links)
- Infinite scroll without pagination
- Deep page hierarchy (4+ levels)
### 2. Core Web Vitals & Performance
**The 3 Core Web Vitals**:
**Largest Contentful Paint (LCP)** - Loading Performance
- Target: < 2.5 seconds
- Measures: When main content loads
- Fix: Optimize images, reduce server response time, use CDN
**First Input Delay (FID)** - Interactivity
- Target: < 100 milliseconds
- Measures: Time until page is interactive
- Fix: Minimize JavaScript, code splitting, defer non-critical JS
**Cumulative Layout Shift (CLS)** - Visual Stability
- Target: < 0.1
- Measures: Unexpected layout shifts
- Fix: Set image dimensions, avoid inserting content above existing content
**Performance Optimization Checklist**:
- [ ] Images optimized (WebP/AVIF, compressed)
- [ ] Lazy loading implemented
- [ ] Critical CSS inlined
- [ ] JavaScript deferred/async
- [ ] CDN for static assets
- [ ] Server response time < 200ms
- [ ] Minified CSS/JS
- [ ] Gzip/Brotli compression enabled
### 3. Mobile-First Optimization
**Mobile SEO Checklist**:
- [ ] Responsive design (adapts to all screen sizes)
- [ ] Viewport meta tag present
- [ ] Touch targets ≥ 44x44px
- [ ] Font size ≥ 16px for body text
- [ ] No horizontal scrolling
- [ ] Mobile page speed < 3 seconds
- [ ] Tap targets well-spaced (48px spacing)
- [ ] No mobile-specific errors in Search Console
**Mobile-Friendly Meta Tag**:
```html
```
### 4. URL Structure & Management
**SEO-Friendly URL Best Practices**:
**Good URLs**:
```
✅ example.com/blog/seo-best-practices
✅ example.com/products/running-shoes
✅ example.com/services/web-design
```
**Bad URLs**:
```
❌ example.com/page.php?id=123&cat=5
❌ example.com/Products_And_Services
❌ example.com/p/12345
```
**URL Guidelines**:
- Use hyphens, not underscores
- Lowercase only
- Include target keyword
- Keep short (< 60 characters)
- Logical hierarchy
- No parameters if possible
- Consistent trailing slash handling
**Redirect Best Practices**:
- Use 301 redirects for moved content
- Avoid redirect chains (A→B→C)
- Update internal links instead of redirecting
- Redirect old URLs to most relevant new page
### 5. HTML & Meta Tag Optimization
**Essential Meta Tags**:
```html
Page Title | Brand Name
```
**Heading Hierarchy**:
```html
Single H1: Primary Page Topic
Main Section 1
Subsection 1.1
Subsection 1.2
Main Section 2
Subsection 2.1
```
### 6. Schema Markup (Structured Data)
**Common Schema Types**:
**Organization**:
```json
{
"@context": "https://schema.org",
"@type": "Organization",
"name": "Company Name",
"url": "https://example.com",
"logo": "https://example.com/logo.png",
"sameAs": [
"https://facebook.com/company",
"https://twitter.com/company",
"https://linkedin.com/company/company"
]
}
```
**Article**:
```json
{
"@context": "https://schema.org",
"@type": "Article",
"headline": "Article Title",
"image": "https://example.com/image.jpg",
"author": {
"@type": "Person",
"name": "Author Name"
},
"publisher": {
"@type": "Organization",
"name": "Publisher",
"logo": {
"@type": "ImageObject",
"url": "https://example.com/logo.png"
}
},
"datePublished": "2025-01-20",
"dateModified": "2025-01-20"
}
```
**BreadcrumbList**:
```json
{
"@context": "https://schema.org",
"@type": "BreadcrumbList",
"itemListElement": [
{
"@type": "ListItem",
"position": 1,
"name": "Home",
"item": "https://example.com"
},
{
"@type": "ListItem",
"position": 2,
"name": "Category",
"item": "https://example.com/category"
}
]
}
```
### 7. Image SEO
**Image Optimization Checklist**:
- [ ] Descriptive file names (not IMG_1234.jpg)
- [ ] Alt text on all images (except decorative)
- [ ] Image dimensions specified (width/height)
- [ ] Lazy loading for below-fold images
- [ ] Modern formats (WebP, AVIF)
- [ ] Compressed (TinyPNG, ImageOptim)
- [ ] Responsive images (srcset)
- [ ] Image sitemap (for image search)
**Example**:
```html
```
### 8. Security & HTTPS
**Security Checklist**:
- [ ] SSL certificate installed and valid
- [ ] All pages served over HTTPS
- [ ] HTTP redirects to HTTPS (301)
- [ ] No mixed content (HTTP resources on HTTPS pages)
- [ ] HSTS header implemented
- [ ] Security headers configured
**Essential Security Headers**:
```
Strict-Transport-Security: max-age=31536000; includeSubDomains
X-Frame-Options: SAMEORIGIN
X-Content-Type-Options: nosniff
Referrer-Policy: strict-origin-when-cross-origin
Permissions-Policy: geolocation=(), microphone=(), camera=()
```
### 9. International & Multi-Language SEO
**Hreflang Implementation**:
```html
```
**Best Practices**:
- Use correct language-region codes (en-US, not just en)
- Include self-referential hreflang
- Include x-default for unmatched regions
- Same URL structure across languages
- Translate meta tags and structured data
### 10. Indexability & Search Console
**Indexability Checklist**:
- [ ] Important pages indexed (check: site:example.com)
- [ ] No accidental noindex tags
- [ ] Sitemap submitted to Search Console
- [ ] Sitemap includes all important pages
- [ ] No crawl errors in Search Console
- [ ] Coverage report clean
- [ ] Mobile usability issues resolved
**XML Sitemap Best Practices**:
```xml
https://example.com/page
2025-01-20
weekly
0.8
```
- Include only canonical URLs
- Update lastmod when content changes
- Split large sitemaps (> 50,000 URLs)
- Exclude noindex pages
- Include images in sitemap or separate image sitemap
---
## Technical SEO Audit Framework
### Phase 1: Discovery (30 minutes)
**Identify**:
- Site type and framework
- Number of pages
- Site structure
- Key templates
- Existing issues
**Tools**:
- Google Search Console
- Screaming Frog (crawl)
- PageSpeed Insights
- Mobile-Friendly Test
### Phase 2: Analysis (2-3 hours)
**Audit all 10 pillars**:
1. Site architecture
2. Core Web Vitals
3. Mobile optimization
4. URL structure
5. HTML/meta tags
6. Schema markup
7. Image SEO
8. Security
9. International (if applicable)
10. Indexability
**Document**:
- Specific issues with file paths
- Severity (Critical/High/Medium/Low)
- Impact on SEO
- Fix recommendations
### Phase 3: Reporting (1 hour)
**Report structure**:
- Executive summary
- Issue count by severity
- Detailed findings by category
- Priority action plan
- Expected impact
---
## Common Technical SEO Issues
### Critical Issues (Fix Immediately)
1. **Site Not Indexed**
- Issue: noindex on all pages
- Impact: Site invisible to search engines
- Fix: Remove noindex tags
2. **Robots.txt Blocking Site**
- Issue: Disallow: / in robots.txt
- Impact: Crawlers can't access site
- Fix: Update robots.txt
3. **No HTTPS**
- Issue: Site on HTTP
- Impact: Security warning, ranking penalty
- Fix: Install SSL certificate
4. **Severe Performance Issues**
- Issue: Page load > 10 seconds
- Impact: High bounce rate, ranking penalty
- Fix: Optimize images, code, server
### High Priority (Fix This Week)
1. **Missing Title Tags**
- Impact: Poor click-through rate
- Fix: Add unique title to every page
2. **Missing Meta Descriptions**
- Impact: Less compelling search results
- Fix: Add compelling descriptions
3. **Not Mobile-Friendly**
- Impact: Mobile ranking penalty
- Fix: Implement responsive design
4. **Broken Internal Links**
- Impact: Poor UX, wasted crawl budget
- Fix: Update or remove broken links
### Medium Priority (Fix This Month)
1. **Suboptimal URL Structure**
- Impact: Missed keyword opportunity
- Fix: Implement clean URLs (with redirects)
2. **Missing Schema Markup**
- Impact: Missed rich snippet opportunity
- Fix: Implement relevant schema types
3. **Images Without Alt Text**
- Impact: Accessibility and image search
- Fix: Add descriptive alt text
4. **Slow Page Speed (3-5s)**
- Impact: Moderate ranking factor
- Fix: Optimize performance
---
## Framework-Specific Considerations
### Next.js SEO Optimization
```typescript
// app/layout.tsx
export const metadata = {
metadataBase: new URL('https://example.com'),
title: {
default: 'Site Name',
template: '%s | Site Name'
},
description: 'Default description',
robots: {
index: true,
follow: true,
},
}
// app/page.tsx
export const metadata = {
title: 'Page Title',
description: 'Page description',
openGraph: {
title: 'Page Title',
description: 'Page description',
images: ['/og-image.jpg'],
},
}
// Generate sitemap
export default function sitemap() {
return [
{
url: 'https://example.com',
lastModified: new Date(),
},
]
}
// robots.txt
export default function robots() {
return {
rules: {
userAgent: '*',
allow: '/',
disallow: '/admin/',
},
sitemap: 'https://example.com/sitemap.xml',
}
}
```
### WordPress SEO
**Essential Plugins**:
- Yoast SEO or Rank Math (on-page optimization)
- WP Rocket or W3 Total Cache (performance)
- Smush or ShortPixel (image optimization)
- Redirection (301 redirects)
**wp-config.php optimizations**:
```php
// Disable file editing
define('DISALLOW_FILE_EDIT', true);
// Enable caching
define('WP_CACHE', true);
// Increase memory limit
define('WP_MEMORY_LIMIT', '256M');
```
### Static Site Generators (Gatsby, Hugo, Jekyll)
**Advantages**:
- Blazing fast (static HTML)
- Inherently secure
- Easy to cache
**SEO Setup**:
- Configure meta tags in templates
- Generate sitemap at build time
- Optimize images during build
- Implement schema in templates
- Configure redirects in netlify.toml or _redirects
---
## Testing & Validation
### Essential Tools
**Free Tools**:
- Google Search Console (indexing, errors)
- Google PageSpeed Insights (performance)
- Google Mobile-Friendly Test
- Google Rich Results Test (schema)
- Lighthouse (comprehensive audit)
- Screaming Frog (free up to 500 URLs)
**Paid Tools**:
- Screaming Frog (full site crawls)
- Ahrefs Site Audit
- SEMrush Site Audit
- Sitebulb
- OnCrawl
### Validation Checklist
After implementing fixes:
- [ ] Run PageSpeed Insights (mobile & desktop)
- [ ] Test with Mobile-Friendly Test
- [ ] Validate schema with Rich Results Test
- [ ] Check Search Console for errors
- [ ] Crawl site with Screaming Frog
- [ ] Verify redirects work correctly
- [ ] Test all critical user flows
- [ ] Check canonical tags point correctly
---
## Monitoring & Maintenance
### Monthly Checks
- [ ] Google Search Console errors
- [ ] Core Web Vitals performance
- [ ] New 404 errors
- [ ] Security issues
- [ ] Mobile usability issues
- [ ] Indexing coverage
### Quarterly Audits
- [ ] Full site crawl
- [ ] Backlink profile review
- [ ] Content freshness audit
- [ ] Technical SEO health check
- [ ] Competitor analysis
---
## Success Metrics
**Technical SEO KPIs**:
- **Crawl Efficiency**: Pages crawled / Total pages
- **Index Coverage**: Pages indexed / Total pages
- **Core Web Vitals**: LCP, FID, CLS scores
- **Mobile Usability**: Issues in Search Console
- **Page Speed**: Load time improvement
- **Error Rate**: 404s, 500s, crawl errors
**Targets**:
- 95%+ important pages indexed
- Core Web Vitals: All "Good"
- 0 critical errors in Search Console
- < 1% 404 error rate
- Mobile page speed < 3 seconds
---
**Version**: 1.0
**Last Updated**: January 2025
**Framework Coverage**: Next.js, WordPress, Static Sites
**Compliance**: Google Search Essentials, Core Web Vitals